A hybrid resonance reactance compensation method for power cable insulation testing

Abstract

The present invention discloses a hybrid resonant reactance compensation method for power cable insulation testing. First, based on the historical insulation test data of the power cable, a simulation model of power parameter changes is constructed. Subsequently, the insulation test data of the target power cable is collected and input into the model to identify current fluctuations and evaluate the performance of the high-voltage reactor. Combined with the idle reactor performance parameter database, the best idle reactor is selected according to the evaluation results, and a hybrid resonant reactance compensation system is constructed with the high-voltage reactor. The test resonant frequency is dynamically matched through the system to generate an adaptive compensation scheme. The present invention improves the accuracy and efficiency of insulation testing, optimizes the configuration of reactor resources, and has high practical value and promotion prospects.

Description

Technical Field

[0001] The invention relates to the technical field of power testing, and in particular to a parallel-parallel resonance reactance compensation method for power cable insulation testing. Background Art

[0002] The insulation performance of power cables is an important guarantee for the safe operation of power systems. Regular insulation testing of high-voltage power cables is one of the key means to ensure that the insulation of cables is in good condition. In actual testing, the long line length and large load capacity of power cables often lead to an increase in the incoming line current in the test circuit, especially in the insulation test of 110kV or 220kV high-voltage power cables. This problem is particularly prominent. Although the traditional series resonance test method can achieve resonant matching between high-voltage reactors and cables to a certain extent, its performance may be limited when the test incoming line current is too large and the reactor's load capacity is insufficient, thereby affecting the effect and efficiency of the insulation test.

[0003] At present, the improvement of some test equipment is mainly focused on improving the performance of high-voltage reactors. However, due to the complexity and randomness of power cable test conditions, it is still difficult to completely solve the problems of limited resonant frequency range and large current fluctuations in the test by optimizing the performance of a single high-voltage reactor. In addition, some high-voltage reactors also have certain limitations in terms of reactance value and adjustable inductance range, which further aggravates the challenges in the test process.

[0004] In order to make more efficient use of existing equipment resources and give full play to the role of idle high-voltage reactors, a reactance compensation method based on "parallel-parallel resonance" is proposed. This method combines the existing high-voltage reactor with the idle high-voltage reactor to construct a parallel-parallel resonance circuit, which significantly improves the load capacity of the equipment and effectively reduces the test incoming line current. On this basis, by dynamically matching the resonant frequency, the shortcomings of the traditional series resonance method under high load and high current conditions are solved.

[0005] The innovative method based on hybrid resonance reactance compensation not only optimizes the test parameters, but also further improves the stability and accuracy of the test through performance compensation strategy. This method can not only maximize the utilization of existing equipment resources, but also significantly improve the effect and efficiency of cable insulation testing, providing a more reliable technical guarantee for the safe operation of power cables. Summary of the invention

[0006] In order to solve at least one of the above technical problems, the present invention proposes a hybrid resonant reactance compensation method for power cable insulation testing.

[0007] A first aspect of the present invention provides a hybrid resonance reactance compensation method for power cable insulation testing, comprising:

[0008] Acquire historical insulation test data of the power cable, the historical insulation test data including historical test power parameters and historical power cable physical parameters, and construct a simulation model of power parameter changes of the power cable during the power cable insulation test according to the historical insulation test data;

[0009] Obtain insulation test data of a target power cable to be tested for insulation, import the insulation test data into the power parameter change simulation model, identify the current fluctuation of the target power cable, and perform performance evaluation on a high-voltage reactor of the power cable insulation test according to the current fluctuation data to obtain a performance evaluation result of the high-voltage reactor;

[0010] Constructing a performance parameter database of idle reactors, identifying the best idle reactor for reactance performance compensation of the high-voltage reactor according to the performance parameter database and the performance evaluation result of the high-voltage reactor, and constructing a hybrid resonance reactance compensation system with the high-voltage reactor and the best idle reactor;

[0011] The resonance frequency of the target power cable during the insulation test is dynamically matched according to the hybrid resonant reactance compensation system to obtain a hybrid resonant reactance compensation scheme for the target power cable during the insulation test.

[0012] In this solution, the historical insulation test data of the power cable is obtained, and the historical insulation test data includes historical test power parameters and historical power cable physical parameters. A simulation model of power parameter changes of the power cable during the power cable insulation test is constructed according to the historical insulation test data, specifically:

[0013] Obtain historical test power parameters and historical power cable physical parameters of the power cable during historical insulation tests, wherein the historical test power parameters include insulation test output current and voltage, power cable incoming line current and voltage, and reactance value, and the historical power cable physical parameters include cable length, cross-sectional area, insulation thickness, and conductivity;

[0014] The historical test power parameters and the historical power cable physical parameters are used to construct a data matrix, and the data matrix is ​​subjected to correlation analysis based on the Pearson correlation coefficient, so as to calculate the correlation coefficient between the output voltage and current of the power cable under different insulation tests and the changes in the incoming current, voltage and reactance value of the power cable under different physical parameters during the insulation test;

[0015] Determine the influence of different insulation test output voltages and currents of the power cable on the changes of the incoming current, voltage and reactance value of the power cable with different physical parameters during the insulation test according to the correlation coefficient, and obtain the influence data;

[0016] A three-dimensional geometric model of the power cable is constructed, and a numerical simulation model of the changes in the incoming current, voltage and reactance values ​​of the power cable with different physical parameters under different insulation test output voltages and currents during the insulation test is constructed according to the influencing data; the numerical simulation model is combined with the three-dimensional geometric model to obtain a simulation model of the changes in the power parameters of the power cable during the insulation test of the power cable.

[0017] In this solution, the insulation test data of the target power cable to be tested is obtained, the insulation test data is imported into the power parameter change simulation model, the current volatility of the target power cable is identified, and the performance of the high-voltage reactor of the power cable insulation test is evaluated according to the current volatility data to obtain the performance evaluation result of the high-voltage reactor, which is specifically:

[0018] Obtaining insulation test data of a target power cable to be tested for insulation, importing the insulation test data into the power parameter change simulation model, and extracting current change data of the target power cable during the insulation test;

[0019] Sorting the current change data according to the time series to construct the current change time series data, and filling the missing values ​​of the current change time series data based on the linear interpolation method;

[0020] Introducing a sliding window method, setting a window size and a window moving step of the sliding window method, performing data calculation within a window on the current change time series data according to the sliding window method, and calculating a current mean and a current standard deviation within each window;

[0021] Evaluate the current fluctuation stability according to the current mean and current standard deviation in each window to obtain a current fluctuation stability evaluation result;

[0022] According to the current fluctuation stability evaluation result, the performance of the high-voltage reactor in the power cable insulation test process is evaluated to obtain the performance evaluation result of the high-voltage reactor, which includes the load capacity, current stability capability, reactance value, and resonant frequency range of the high-voltage reactor.

[0023] In this solution, the performance parameter database of the idle reactor is constructed, and the best idle reactor for reactance performance compensation of the high-voltage reactor is identified according to the performance parameter database and the performance evaluation result of the high-voltage reactor, and the high-voltage reactor and the best idle reactor are used to construct a hybrid resonance reactance compensation system, specifically:

[0024] Obtaining performance parameter data of idle reactors in the target test site, the performance parameter data including rated voltage and current, inductance value and adjustable range of inductance value, resonant frequency range, load capacity, and degree of reactor performance degradation;

[0025] Constructing a performance parameter database of idle reactors, and importing the performance parameter data into the performance parameter database;

[0026] Obtain the high-voltage reactor performance requirement data required by the target power cable during the insulation test, compare the performance requirement data with the high-voltage reactor performance evaluation result, and determine the performance deviation of the high-voltage reactor, which includes insufficient load capacity, limited resonant frequency range, excessive incoming line current, and insufficient reactance value;

[0027] Determining the performance compensation capability of each idle reactor for the high-voltage reactor according to the performance parameter database, comparing the performance compensation capability with the performance deviation, and calculating the matching degree between the performance compensation capability and the performance deviation of each idle reactor;

[0028] Selecting an idle reactor with the highest matching degree as the best idle reactor for the high-voltage reactor to compensate for reactance performance;

[0029] Determine a circuit connection mode for using an optimal idle reactor to compensate the performance of a high-voltage reactor according to the performance deviation, wherein the circuit connection mode includes series resonance and parallel resonance;

[0030] The high-voltage reactor is connected to the optimal idle reactor according to the circuit connection method to construct a hybrid resonance reactance compensation system during the target power cable insulation test.

[0031] In this solution, the resonant frequency of the target power cable during the insulation test is dynamically matched according to the hybrid resonant reactance compensation system to obtain a hybrid resonant reactance compensation solution for the target power cable during the insulation test, specifically:

[0032] Monitor the incoming current of the target power cable in real time during the insulation test to obtain the monitoring current change data;

[0033] Determine equivalent parameters of the target power cable load according to the physical parameters of the target power cable, wherein the equivalent parameters include equivalent capacitance, equivalent inductance, equivalent resistance, and transmission characteristic impedance of the target power cable;

[0034] Determine the initial resonant frequency range of the target power cable according to the equivalent parameters, introduce a dynamic frequency matching algorithm, and set a frequency scanning compensation of the dynamic frequency matching algorithm;

[0035] Performing a scanning operation on the initial resonant frequency range according to the frequency scanning step length, and for each frequency point in the initial resonant frequency range, calculating the equivalent inductance value of each frequency point according to the monitored current change data and solving the resonant frequency;

[0036] Identify the optimal resonant frequency point of each current data point during the monitoring current change of the target power cable during the insulation test according to the equivalent inductance value and the solved resonant frequency;

[0037] Acquire the real-time resonant frequency information of the target power cable during the insulation test, compare the real-time resonant frequency information with the optimal resonant frequency point, and if the difference between the real-time resonant frequency and the optimal resonant frequency point is greater than a preset value, perform a correction operation on the real-time resonant frequency according to the optimal resonant frequency point;

[0038] Determine the adjustment parameters of the hybrid resonance reactance compensation system according to the optimal resonance frequency point, control the hybrid resonance reactance compensation system according to the adjustment parameters, and obtain the hybrid resonance reactance compensation scheme of the target power cable during the insulation test;

[0039] The reactance effect of the hybrid resonance reactance compensation scheme is monitored in real time, and the hybrid resonance reactance compensation scheme is optimized according to the reactance compensation effect.

[0040] In this solution, the reactance effect of the hybrid resonance reactance compensation solution is monitored in real time, and the hybrid resonance reactance compensation solution is optimized according to the reactance compensation effect, specifically:

[0041] Performing reactance compensation operation on the target power cable insulation test according to the hybrid resonance reactance compensation scheme, and monitoring the resonant frequency change information during the reactance compensation operation in real time;

[0042] Acquire resonance target frequency information according to the hybrid resonance reactance compensation scheme, and determine the degree of resonance frequency drift according to the resonance frequency change information and the resonance target frequency information;

[0043] If the degree of resonant frequency drift is greater than a preset value, obtaining current control parameters of the hybrid resonant reactance compensation system, and determining the error degree of the hybrid resonant reactance compensation system according to the current control parameters and the degree of resonant frequency drift;

[0044] Introducing a PID control algorithm, analyzing the error degree of the hybrid resonant reactance compensation system according to the PID control algorithm, and determining the compensation value of the current control parameter of the hybrid resonant reactance compensation system;

[0045] According to the compensation value, a control parameter optimization operation is performed on the current control parameters of the hybrid resonant reactance compensation system in the hybrid resonant reactance compensation scheme to obtain a hybrid resonant reactance compensation optimization scheme.

[0046] The second aspect of the present invention further provides a hybrid resonance reactance compensation system for power cable insulation test, the system comprising: a memory, a processor, the memory comprising a hybrid resonance reactance compensation method program for power cable insulation test, the hybrid resonance reactance compensation method program for power cable insulation test being executed by the processor to implement the following steps:

[0047] Acquire historical insulation test data of the power cable, the historical insulation test data including historical test power parameters and historical power cable physical parameters, and construct a simulation model of power parameter changes of the power cable during the power cable insulation test according to the historical insulation test data;

[0048] Obtain insulation test data of a target power cable to be tested for insulation, import the insulation test data into the power parameter change simulation model, identify the current fluctuation of the target power cable, and perform performance evaluation on a high-voltage reactor of the power cable insulation test according to the current fluctuation data to obtain a performance evaluation result of the high-voltage reactor;

[0049] Constructing a performance parameter database of idle reactors, identifying the best idle reactor for reactance performance compensation of the high-voltage reactor according to the performance parameter database and the performance evaluation result of the high-voltage reactor, and constructing a hybrid resonance reactance compensation system with the high-voltage reactor and the best idle reactor;

[0050] The resonance frequency of the target power cable during the insulation test is dynamically matched according to the hybrid resonant reactance compensation system to obtain a hybrid resonant reactance compensation scheme for the target power cable during the insulation test.

[0051] The present invention discloses a hybrid resonant reactance compensation method for power cable insulation testing. First, based on the historical insulation test data of the power cable, a simulation model of power parameter changes is constructed. Subsequently, the insulation test data of the target power cable is collected and input into the model to identify current fluctuations and evaluate the performance of the high-voltage reactor. Combined with the idle reactor performance parameter database, the best idle reactor is selected according to the evaluation results, and a hybrid resonant reactance compensation system is constructed with the high-voltage reactor. The test resonant frequency is dynamically matched through the system to generate an adaptive compensation scheme. The present invention improves the accuracy and efficiency of insulation testing, optimizes the configuration of reactor resources, and has high practical value and promotion prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 A flow chart of a parallel-parallel resonance reactance compensation method for power cable insulation testing according to the present invention is shown;

[0053] Figure 2 A flow chart of constructing a power parameter variation simulation model according to the present invention is shown;

[0054] Figure 3 A flow chart showing the performance evaluation result of a high-voltage reactor obtained by the present invention;

[0055] Figure 4 A block diagram of a series-parallel resonance reactance compensation system for power cable insulation testing according to the present invention is shown. DETAILED DESCRIPTION

[0056] In order to more clearly understand the above-mentioned purpose, features and advantages of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0057] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited to the specific embodiments disclosed below.

[0058] Figure 1 The flowchart of a hybrid resonance reactance compensation method for power cable insulation testing of the present invention is shown.

[0059] like Figure 1 As shown, the first aspect of the present invention provides a hybrid resonance reactance compensation method for power cable insulation testing, comprising:

[0060] S102, obtaining historical insulation test data of the power cable, wherein the historical insulation test data includes historical test power parameters and historical power cable physical parameters, and constructing a simulation model of power parameter changes of the power cable during the power cable insulation test according to the historical insulation test data;

[0061] S104, obtaining insulation test data of a target power cable to be tested for insulation, importing the insulation test data into the power parameter change simulation model, identifying current fluctuation of the target power cable, and performing performance evaluation on a high-voltage reactor of the power cable insulation test according to the current fluctuation data to obtain a performance evaluation result of the high-voltage reactor;

[0062] S106, constructing a performance parameter database of idle reactors, identifying the best idle reactor for reactance performance compensation of the high-voltage reactor according to the performance parameter database and the performance evaluation result of the high-voltage reactor, and constructing a hybrid resonant reactance compensation system with the high-voltage reactor and the best idle reactor;

[0063] S108, dynamically matching the resonant frequency of the target power cable during the insulation test according to the series-parallel resonant reactance compensation system to obtain a series-parallel resonant reactance compensation scheme for the target power cable during the insulation test.

[0064] It should be noted that by obtaining the historical insulation test data of the power cable to construct a power parameter change simulation model of the power cable, it is helpful to accurately predict the change law of the current, voltage, etc. of the power cable in the insulation test. This model can provide efficient parameter reference for subsequent tests, reduce the blindness of test parameter adjustment, and improve the accuracy and efficiency of the test; by analyzing the current fluctuation in the target power cable test through the power parameter change simulation model, the actual performance of the high-voltage reactor under the test conditions, such as load capacity, current stability, etc., can be quickly evaluated; by constructing a performance parameter database of idle reactors, combined with the target test requirements and the performance deviation of the high-voltage reactor, the best compensation equipment can be accurately identified to achieve optimal utilization of resources, and the idle reactor and the currently used high-voltage reactor are combined into a collaborative working system through the hybrid resonance method, which significantly improves the load capacity, expands the resonant frequency range, and effectively reduces the incoming line current in the test loop, solving the limitation problem of insufficient equipment performance under the traditional series resonance method. By dynamically matching the resonant frequency during the insulation test of the target power cable, a hybrid resonance reactance compensation scheme is constructed, which realizes the real-time dynamic adjustment of the resonant frequency in the insulation test of the target power cable, ensuring that the test loop is always in the best resonance state. The optimized compensation scheme can effectively cope with the changes in load parameters during the test, improve the stability and reliability of the test, and reduce the workload of manual frequency adjustment.

[0065] Figure 2 A flow chart of constructing a power parameter variation simulation model according to the present invention is shown.

[0066] According to an embodiment of the present invention, the historical insulation test data of the power cable is obtained, and the historical insulation test data includes historical test power parameters and historical power cable physical parameters. A simulation model of power parameter changes of the power cable during the power cable insulation test is constructed according to the historical insulation test data, specifically:

[0067] S202, obtaining historical test power parameters and historical power cable physical parameters during historical insulation test of the power cable, wherein the historical test power parameters include insulation test output current and voltage, incoming line current and voltage of the power cable, and reactance value, and the historical power cable physical parameters include cable length, cross-sectional area, insulation thickness, and conductivity;

[0068] S204, constructing a data matrix with the historical test power parameters and the historical power cable physical parameters, performing correlation analysis on the data matrix based on the Pearson correlation coefficient, and calculating the correlation coefficient between the output voltage and current of different insulation tests of the power cable during the insulation test and the changes in the incoming current, voltage, and reactance value of the power cable with different physical parameters;

[0069] S206, determining, according to the correlation coefficient, the influence of different insulation test output voltages and currents of the power cable during the insulation test on the changes in the incoming current, voltage, and reactance value of the power cable with different physical parameters, and obtaining influence data;

[0070] S208, constructing a three-dimensional geometric model of the power cable, and constructing a numerical simulation model of the changes in the incoming current, voltage, and reactance values ​​of the power cable with different physical parameters due to different insulation test output voltages and currents during the insulation test of the power cable based on the influencing data, and combining the numerical simulation model with the three-dimensional geometric model to obtain a simulation model of the changes in the power parameters of the power cable during the insulation test of the power cable.

[0071] It should be noted that the Pearson correlation coefficient analysis can quantify the correlation between the power parameters (such as output voltage and current) and the physical properties of the cable (such as length, cross-sectional area, insulation thickness, and conductivity) in the power cable test. This quantitative analysis helps to discover the main factors affecting the test performance and the intrinsic coupling relationship between the parameters. The correlation coefficient is used to screen out the physical parameters and power parameters that have a significant impact on the power cable test process, exclude variables that contribute less to the results, and reduce redundant data in model construction. According to the correlation and influence degree between different parameters, reference values ​​can be provided for the setting of the test output voltage, current, and reactance value, thereby optimizing the test parameter configuration, reducing the test error and equipment operation load. Through the correlation-based data analysis method, the model can adapt to the changes in different cable characteristics and test conditions, and has a wider applicability. By constructing an accurate simulation model for power parameter changes, the response of the cable during the test can be accurately predicted, providing a data basis for equipment performance evaluation (such as the load capacity and reactance value of high-voltage reactors). The influencing data reflect the strength of the correlation between the electrical parameters (test output voltage, current) and the physical parameters of the cable (such as length, cross-sectional area, insulation thickness, and conductivity). Positive correlation: the parameter increases with the increase of the test output voltage or current (the value is close to 1); negative correlation: the parameter decreases with the increase of the test output voltage or current (the value is close to -1); irrelevant: there is no significant relationship between the parameters (the value is close to 0).

[0072] Figure 3 A flow chart of obtaining a high-voltage reactor performance evaluation result according to the present invention is shown.

[0073] According to an embodiment of the present invention, the insulation test data of the target power cable to be tested for insulation is obtained, the insulation test data is imported into the power parameter change simulation model, the current volatility of the target power cable is identified, and the performance of the high-voltage reactor of the power cable insulation test is evaluated according to the current volatility data to obtain the performance evaluation result of the high-voltage reactor, which is specifically:

[0074] S302, obtaining insulation test data of a target power cable to be tested for insulation, importing the insulation test data into the power parameter change simulation model, and extracting current change data of the target power cable during the insulation test;

[0075] S304, sorting the current change data according to the time series, constructing the current change time series data, and filling the missing values ​​of the current change time series data based on the linear interpolation method;

[0076] S306, introducing a sliding window method, setting a window size and a window moving step of the sliding window method, performing data calculation within a window on the current change time series data according to the sliding window method, and calculating a current mean and a current standard deviation within each window;

[0077] S308, evaluating the current fluctuation stability according to the current mean value and the current standard deviation in each window to obtain a current fluctuation stability evaluation result;

[0078] S310, performing a performance evaluation on the high-voltage reactor during the power cable insulation test according to the current fluctuation stability evaluation result, and obtaining a performance evaluation result of the high-voltage reactor, wherein the performance evaluation result includes the load capacity, current stability capability, reactance value, and resonant frequency range of the high-voltage reactor.

[0079] It should be noted that by using the sliding window method, the current data is segmented and analyzed in the time series (the mean and standard deviation in the window are calculated), and the fluctuation characteristics of the current in different time periods can be accurately quantified. By segmented calculation and dynamic analysis of the current change data, accurate quantification, abnormal detection and trend analysis of the current fluctuation characteristics are achieved, and the ability to evaluate the stability of the fluctuation is significantly improved; the performance of the high-voltage reactor under the working conditions of only a single high-voltage reactor and no hybrid resonance is performed during the power cable insulation test is evaluated by the stability of the current fluctuation, and whether the reactance value of the reactor can adapt to the changes under different test conditions is further judged, and whether it can maintain a stable resonant frequency range during the entire test process. The insulation test data are the test power parameters and the physical parameters of the power cable, and the test power parameters include the insulation test output current and voltage.

[0080] According to an embodiment of the present invention, the performance parameter database of the idle reactor is constructed, and the best idle reactor for compensating the reactance performance of the high-voltage reactor is identified according to the performance parameter database and the performance evaluation result of the high-voltage reactor, and the high-voltage reactor and the best idle reactor are used to construct a hybrid resonance reactance compensation system, specifically:

[0081] Obtaining performance parameter data of idle reactors in the target test site, the performance parameter data including rated voltage and current, inductance value and adjustable range of inductance value, resonant frequency range, load capacity, and degree of reactor performance degradation;

[0082] Constructing a performance parameter database of idle reactors, and importing the performance parameter data into the performance parameter database;

[0083] Obtain the high-voltage reactor performance requirement data required by the target power cable during the insulation test, compare the performance requirement data with the high-voltage reactor performance evaluation result, and determine the performance deviation of the high-voltage reactor, which includes insufficient load capacity, limited resonant frequency range, excessive incoming line current, and insufficient reactance value;

[0084] Determining the performance compensation capability of each idle reactor for the high-voltage reactor according to the performance parameter database, comparing the performance compensation capability with the performance deviation, and calculating the matching degree between the performance compensation capability and the performance deviation of each idle reactor;

[0085] Selecting an idle reactor with the highest matching degree as the best idle reactor for the high-voltage reactor to compensate for reactance performance;

[0086] Determine a circuit connection mode for using an optimal idle reactor to compensate the performance of a high-voltage reactor according to the performance deviation, wherein the circuit connection mode includes series resonance and parallel resonance;

[0087] The high-voltage reactor is connected to the optimal idle reactor according to the circuit connection method to construct a hybrid resonance reactance compensation system during the target power cable insulation test.

[0088] It should be noted that by combining the idle reactors that do not meet the performance requirements of high-voltage reactors in the target test site with the existing high-voltage reactors, the load capacity of the system can be significantly improved. The original single reactor may not be able to withstand a large load, but through the hybrid resonance method, the entire system can operate stably under a higher load, thereby coping with the large load requirements in the 110kV / 220kV high-voltage power cable insulation test. Through the optimization of the hybrid resonance system, the incoming line current has been greatly reduced during the test. This is because the addition of idle reactors effectively shares the power load, reduces the current carried by the high-voltage reactor alone, and thus reduces the incoming line current in the power cable test circuit, reducing the burden on the power equipment. The hybrid resonance system can expand the resonant frequency range of the reactor, allowing the system to adapt to a wider range of test conditions. Especially in high-voltage cable tests, the frequency adjustment range of the reactor is crucial to the stable test process. The hybrid resonance system can ensure the dynamic matching of the resonant frequency, thereby maintaining the stability of the test. By selecting an idle reactor with the highest performance deviation match of the existing high-voltage reactor, its compensation capability can be maximized to ensure that the reactor performs best during the power cable insulation test. The best matching reactor can effectively compensate for the deficiencies of the existing reactor in terms of load capacity, resonant frequency range, etc., so that the performance of the test circuit reaches the optimal state. The performance compensation capability includes load capacity compensation, current stability compensation, resonant frequency range compensation, and reactance value compensation.

[0089] According to an embodiment of the present invention, the resonant frequency of the target power cable during the insulation test is dynamically matched according to the hybrid resonant reactance compensation system to obtain a hybrid resonant reactance compensation scheme for the target power cable during the insulation test, specifically:

[0090] Monitor the incoming current of the target power cable in real time during the insulation test to obtain the monitoring current change data;

[0091] Determine equivalent parameters of the target power cable load according to the physical parameters of the target power cable, wherein the equivalent parameters include equivalent capacitance, equivalent inductance, equivalent resistance, and transmission characteristic impedance of the target power cable;

[0092] Determine the initial resonant frequency range of the target power cable according to the equivalent parameters, introduce a dynamic frequency matching algorithm, and set a frequency scanning compensation of the dynamic frequency matching algorithm;

[0093] Performing a scanning operation on the initial resonant frequency range according to the frequency scanning step length, and for each frequency point in the initial resonant frequency range, calculating the equivalent inductance value of each frequency point according to the monitored current change data and solving the resonant frequency;

[0094] Identify the optimal resonant frequency point of each current data point during the monitoring current change of the target power cable during the insulation test according to the equivalent inductance value and the solved resonant frequency;

[0095] Acquire the real-time resonant frequency information of the target power cable during the insulation test, compare the real-time resonant frequency information with the optimal resonant frequency point, and if the difference between the real-time resonant frequency and the optimal resonant frequency point is greater than a preset value, perform a correction operation on the real-time resonant frequency according to the optimal resonant frequency point;

[0096] Determine the adjustment parameters of the hybrid resonance reactance compensation system according to the optimal resonance frequency point, control the hybrid resonance reactance compensation system according to the adjustment parameters, and obtain the hybrid resonance reactance compensation scheme of the target power cable during the insulation test;

[0097] The reactance effect of the hybrid resonance reactance compensation scheme is monitored in real time, and the hybrid resonance reactance compensation scheme is optimized according to the reactance compensation effect.

[0098] It should be noted that during the insulation test of the target power cable, the current change data is first collected by real-time monitoring of the incoming current of the power cable. These data reflect the changes in the electrical performance of the power cable during the test and provide the necessary real-time input for the subsequent resonant frequency matching; based on the physical parameters of the power cable (such as length, cross-sectional area, insulation thickness, etc.), the equivalent parameters of the power cable load (including equivalent capacitance, equivalent inductance, equivalent resistance and transmission characteristic impedance) are determined. These equivalent parameters help define the electrical characteristics of the power cable, thereby predicting its current response during the insulation test; based on the equivalent parameters of the power cable, its resonant frequency range during the insulation test is preliminarily determined. The resonant frequency is one of the common electrical characteristics of the power cable and the test circuit, which affects the current response of the system. If the resonant frequency does not match, it may cause excessive or unstable current; the dynamic frequency matching algorithm is introduced to scan the initial resonant frequency range to identify the best resonant frequency. Once the real-time resonant frequency information of the target power cable during the insulation test is obtained, the algorithm will compare it with the pre-calculated optimal resonant frequency point. If the difference between the two exceeds the preset threshold, the system will automatically correct and adjust the real-time resonant frequency to make it as close to the optimal frequency point as possible. This correction mechanism can ensure that during the test, the reactor and the power cable are always kept in the best resonant state, thereby avoiding the situation where the current is too large, too small or unstable due to frequency mismatch. According to the corrected optimal resonant frequency point, the adjustment parameters of the hybrid resonance reactance compensation system are determined. These adjustment parameters are used to control and optimize the compensation system in real time, so that it can accurately adjust the reactance value and frequency response, and further reduce the impact of current fluctuations during the test. Through dynamic compensation of the reactor and power cable system, the system's load capacity, current stability and reactance performance are optimized, thereby solving the problem of excessive current in the target power cable, avoiding excessive current from breaking through the insulation layer, affecting the accuracy of the insulation test, reducing the reactor load, and improving the efficiency and stability of the test system. The hybrid resonance is a coexistence of series resonance and parallel resonance; the adjustment parameters include the resonant frequency, the reactance value of the reactor, the number of series or parallel reactors, etc.

[0099] According to an embodiment of the present invention, the real-time monitoring of the reactance effect of the hybrid resonance reactance compensation scheme and the optimization operation of the hybrid resonance reactance compensation scheme according to the reactance compensation effect are specifically as follows:

[0100] Performing reactance compensation operation on the target power cable insulation test according to the hybrid resonance reactance compensation scheme, and monitoring the resonant frequency change information during the reactance compensation operation in real time;

[0101] Acquire resonance target frequency information according to the hybrid resonance reactance compensation scheme, and determine the degree of resonance frequency drift according to the resonance frequency change information and the resonance target frequency information;

[0102] If the degree of resonant frequency drift is greater than a preset value, obtaining current control parameters of the hybrid resonant reactance compensation system, and determining the error degree of the hybrid resonant reactance compensation system according to the current control parameters and the degree of resonant frequency drift;

[0103] Introducing a PID control algorithm, analyzing the error degree of the hybrid resonant reactance compensation system according to the PID control algorithm, and determining the compensation value of the current control parameter of the hybrid resonant reactance compensation system;

[0104] According to the compensation value, a control parameter optimization operation is performed on the current control parameters of the hybrid resonant reactance compensation system in the hybrid resonant reactance compensation scheme to obtain a hybrid resonant reactance compensation optimization scheme.

[0105] It should be noted that during the test, the change in cable capacitance due to temperature rise effect or environmental changes may cause the resonant frequency to drift. By monitoring the system frequency change, the compensation reactance value is adjusted in real time using the automatic control algorithm to correct the resonant frequency deviation, optimize the reactance compensation performance, and maintain a stable resonant state. The introduction of the PID control algorithm (proportional-integral-differential control algorithm) can automatically analyze the error and make adjustments when the resonant frequency drift is detected. The PID controller automatically adjusts the control parameters (such as the reactance value of the reactor, the resonant frequency, etc.) by measuring the system error (i.e. the deviation of the resonant frequency) in real time to ensure the minimum deviation between the system's resonant frequency and the target frequency. This automated control process greatly reduces the workload of manual adjustment and improves the accuracy and efficiency of the test. Due to the dynamic changes in the power cable and equipment parameters during the test, the current may be unstable or the system may enter a non-resonant state. This technology optimizes the compensation scheme and dynamically adjusts the working parameters of the reactor to ensure that the power cable is always in a stable resonant state during the test, thereby reducing current fluctuations.

[0106] Figure 4 A block diagram of a series-parallel resonance reactance compensation system for power cable insulation testing according to the present invention is shown.

[0107] The second aspect of the present invention further provides a hybrid resonance reactance compensation system 4 for power cable insulation test, the system comprising: a memory 41, a processor 42, the memory comprising a hybrid resonance reactance compensation method program for power cable insulation test, the hybrid resonance reactance compensation method program for power cable insulation test being executed by the processor to implement the following steps:

[0108] Acquire historical insulation test data of the power cable, the historical insulation test data including historical test power parameters and historical power cable physical parameters, and construct a simulation model of power parameter changes of the power cable during the power cable insulation test according to the historical insulation test data;

[0109] Obtain insulation test data of a target power cable to be tested for insulation, import the insulation test data into the power parameter change simulation model, identify the current fluctuation of the target power cable, and perform performance evaluation on a high-voltage reactor of the power cable insulation test according to the current fluctuation data to obtain a performance evaluation result of the high-voltage reactor;

[0110] Constructing a performance parameter database of idle reactors, identifying the best idle reactor for reactance performance compensation of the high-voltage reactor according to the performance parameter database and the performance evaluation result of the high-voltage reactor, and constructing a hybrid resonance reactance compensation system with the high-voltage reactor and the best idle reactor;

[0111] The resonance frequency of the target power cable during the insulation test is dynamically matched according to the hybrid resonant reactance compensation system to obtain a hybrid resonant reactance compensation scheme for the target power cable during the insulation test.

[0112] The present invention discloses a hybrid resonant reactance compensation method for power cable insulation testing. First, based on the historical insulation test data of the power cable, a simulation model of power parameter changes is constructed. Subsequently, the insulation test data of the target power cable is collected and input into the model to identify current fluctuations and evaluate the performance of the high-voltage reactor. Combined with the idle reactor performance parameter database, the best idle reactor is selected according to the evaluation results, and a hybrid resonant reactance compensation system is constructed with the high-voltage reactor. The test resonant frequency is dynamically matched through the system to generate an adaptive compensation scheme. The present invention improves the accuracy and efficiency of insulation testing, optimizes the configuration of reactor resources, and has high practical value and promotion prospects.

[0113] In the several embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as: multiple units or components can be combined, or can be integrated into another system, or some features can be ignored or not executed. In addition, the coupling, direct coupling, or communication connection between the components shown or discussed can be through some interfaces, and the indirect coupling or communication connection of the devices or units can be electrical, mechanical or other forms.

[0114] The units described above as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units; they may be located in one place or distributed on multiple network units; some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0115] In addition, all functional units in the embodiments of the present invention may be integrated into one processing unit, or each unit may be separately used as a unit, or two or more units may be integrated into one unit; the above-mentioned integrated units may be implemented in the form of hardware or in the form of hardware plus software functional units.

[0116] A person of ordinary skill in the art can understand that: all or part of the steps of implementing the above method embodiments can be completed by hardware related to program instructions, and the aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it executes the steps of the above method embodiments; and the aforementioned storage medium includes: mobile storage devices, read-only memories (ROM, Read-Only Memory), random access memories (RAM, Random Access Memory), magnetic disks or optical disks, and other media that can store program codes.

[0117] Alternatively, if the above-mentioned integrated unit of the present invention is implemented in the form of a software function module and sold or used as an independent product, it can also be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the embodiment of the present invention can be essentially or partly reflected in the form of a software product that contributes to the prior art. The computer software product is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the methods described in each embodiment of the present invention. The aforementioned storage medium includes: various media that can store program codes, such as mobile storage devices, ROM, RAM, magnetic disks or optical disks.

[0118] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A hybrid resonance reactance compensation method for power cable insulation testing, characterized in that: The following steps are involved: Acquire historical insulation test data of the power cable, the historical insulation test data including historical test power parameters and historical power cable physical parameters, and construct a simulation model of power parameter changes of the power cable during the power cable insulation test according to the historical insulation test data; Obtain insulation test data of a target power cable to be tested for insulation, import the insulation test data into the power parameter change simulation model, identify the current fluctuation of the target power cable, and perform performance evaluation on a high-voltage reactor of the power cable insulation test according to the current fluctuation data to obtain a performance evaluation result of the high-voltage reactor; Constructing a performance parameter database of idle reactors, identifying the best idle reactor for reactance performance compensation of the high-voltage reactor according to the performance parameter database and the performance evaluation result of the high-voltage reactor, and constructing a hybrid resonance reactance compensation system with the high-voltage reactor and the best idle reactor; The resonance frequency of the target power cable during the insulation test is dynamically matched according to the hybrid resonant reactance compensation system to obtain a hybrid resonant reactance compensation scheme for the target power cable during the insulation test.

2. A series-parallel resonance reactance compensation method for power cable insulation test according to claim 1, characterized in that: The historical insulation test data of the power cable is obtained, the historical insulation test data includes historical test power parameters and historical power cable physical parameters, and a power parameter change simulation model of the power cable during the power cable insulation test is constructed according to the historical insulation test data, specifically: Obtain historical test power parameters and historical power cable physical parameters of the power cable during historical insulation tests, wherein the historical test power parameters include insulation test output current and voltage, power cable incoming line current and voltage, and reactance value, and the historical power cable physical parameters include cable length, cross-sectional area, insulation thickness, and conductivity; The historical test power parameters and the historical power cable physical parameters are used to construct a data matrix, and the data matrix is ​​subjected to correlation analysis based on the Pearson correlation coefficient, so as to calculate the correlation coefficient between the output voltage and current of the power cable under different insulation tests and the changes in the incoming current, voltage and reactance value of the power cable under different physical parameters during the insulation test; Determine the influence of different insulation test output voltages and currents of the power cable on the changes of the incoming current, voltage and reactance value of the power cable with different physical parameters during the insulation test according to the correlation coefficient, and obtain the influence data; A three-dimensional geometric model of the power cable is constructed, and a numerical simulation model of the changes in the incoming current, voltage and reactance values ​​of the power cable with different physical parameters under different insulation test output voltages and currents during the insulation test is constructed according to the influencing data; the numerical simulation model is combined with the three-dimensional geometric model to obtain a simulation model of the changes in the power parameters of the power cable during the insulation test of the power cable.

3. A series-parallel resonance reactance compensation method for power cable insulation test according to claim 1, characterized in that: The insulation test data of the target power cable to be tested is obtained, the insulation test data is imported into the power parameter change simulation model, the current volatility of the target power cable is identified, and the performance of the high-voltage reactor of the power cable insulation test is evaluated according to the current volatility data to obtain the performance evaluation result of the high-voltage reactor, which is specifically: Obtaining insulation test data of a target power cable to be tested for insulation, importing the insulation test data into the power parameter change simulation model, and extracting current change data of the target power cable during the insulation test; Sorting the current change data according to the time series to construct the current change time series data, and filling the missing values ​​of the current change time series data based on the linear interpolation method; Introducing a sliding window method, setting a window size and a window moving step of the sliding window method, performing data calculation within a window on the current change time series data according to the sliding window method, and calculating a current mean and a current standard deviation within each window; Evaluate the current fluctuation stability according to the current mean and current standard deviation in each window to obtain a current fluctuation stability evaluation result; According to the current fluctuation stability evaluation result, the performance of the high-voltage reactor in the power cable insulation test process is evaluated to obtain the performance evaluation result of the high-voltage reactor, which includes the load capacity, current stability capability, reactance value, and resonant frequency range of the high-voltage reactor.

4. A series-parallel resonance reactance compensation method for power cable insulation testing according to claim 1, characterized in that: The method of constructing a performance parameter database of an idle reactor, identifying the best idle reactor for reactance performance compensation of the high-voltage reactor according to the performance parameter database and the performance evaluation result of the high-voltage reactor, and constructing a hybrid resonance reactance compensation system with the high-voltage reactor and the best idle reactor, is specifically as follows: Obtaining performance parameter data of idle reactors in the target test site, the performance parameter data including rated voltage and current, inductance value and adjustable range of inductance value, resonant frequency range, load capacity, and degree of reactor performance degradation; Constructing a performance parameter database of idle reactors, and importing the performance parameter data into the performance parameter database; Obtain the high-voltage reactor performance requirement data required by the target power cable during the insulation test, compare the performance requirement data with the high-voltage reactor performance evaluation result, and determine the performance deviation of the high-voltage reactor, which includes insufficient load capacity, limited resonant frequency range, excessive incoming line current, and insufficient reactance value; Determining the performance compensation capability of each idle reactor for the high-voltage reactor according to the performance parameter database, comparing the performance compensation capability with the performance deviation, and calculating the matching degree between the performance compensation capability and the performance deviation of each idle reactor; Selecting an idle reactor with the highest matching degree as the best idle reactor for the high-voltage reactor to compensate for reactance performance; Determine a circuit connection mode for using an optimal idle reactor to compensate the performance of a high-voltage reactor according to the performance deviation, wherein the circuit connection mode includes series resonance and parallel resonance; The high-voltage reactor is connected to the optimal idle reactor according to the circuit connection method to construct a hybrid resonance reactance compensation system during the target power cable insulation test.

5. A series-parallel resonance reactance compensation method for power cable insulation test according to claim 1, characterized in that: The hybrid resonance reactance compensation scheme for the target power cable during the insulation test is obtained by dynamically matching the resonance frequency of the target power cable during the insulation test according to the hybrid resonance reactance compensation system, specifically: Monitor the incoming current of the target power cable in real time during the insulation test to obtain the monitoring current change data; Determine equivalent parameters of the target power cable load according to the physical parameters of the target power cable, wherein the equivalent parameters include equivalent capacitance, equivalent inductance, equivalent resistance, and transmission characteristic impedance of the target power cable; Determine the initial resonant frequency range of the target power cable according to the equivalent parameters, introduce a dynamic frequency matching algorithm, and set a frequency scanning compensation of the dynamic frequency matching algorithm; Performing a scanning operation on the initial resonant frequency range according to the frequency scanning step length, and for each frequency point in the initial resonant frequency range, calculating the equivalent inductance value of each frequency point according to the monitored current change data and solving the resonant frequency; Identify the optimal resonant frequency point of each current data point during the monitoring current change of the target power cable during the insulation test according to the equivalent inductance value and the solved resonant frequency; Acquire the real-time resonant frequency information of the target power cable during the insulation test, compare the real-time resonant frequency information with the optimal resonant frequency point, and if the difference between the real-time resonant frequency and the optimal resonant frequency point is greater than a preset value, perform a correction operation on the real-time resonant frequency according to the optimal resonant frequency point; Determine adjustment parameters of the hybrid resonance reactance compensation system according to the optimal resonance frequency point, control the hybrid resonance reactance compensation system according to the adjustment parameters, and obtain a hybrid resonance reactance compensation scheme for the target power cable during the insulation test; The reactance effect of the hybrid resonance reactance compensation scheme is monitored in real time, and the hybrid resonance reactance compensation scheme is optimized according to the reactance compensation effect.

6. A series-parallel resonance reactance compensation method for power cable insulation testing according to claim 5, characterized in that: The real-time monitoring of the reactance effect of the hybrid resonance reactance compensation scheme and the optimization of the hybrid resonance reactance compensation scheme according to the reactance compensation effect are specifically as follows: Performing reactance compensation operation on the target power cable insulation test according to the hybrid resonance reactance compensation scheme, and monitoring the resonant frequency change information during the reactance compensation operation in real time; Acquire resonance target frequency information according to the hybrid resonance reactance compensation scheme, and determine the degree of resonance frequency drift according to the resonance frequency change information and the resonance target frequency information; If the degree of resonant frequency drift is greater than a preset value, obtaining current control parameters of the hybrid resonant reactance compensation system, and determining the error degree of the hybrid resonant reactance compensation system according to the current control parameters and the degree of resonant frequency drift; Introducing a PID control algorithm, analyzing the error degree of the hybrid resonant reactance compensation system according to the PID control algorithm, and determining the compensation value of the current control parameter of the hybrid resonant reactance compensation system; According to the compensation value, a control parameter optimization operation is performed on the current control parameters of the hybrid resonant reactance compensation system in the hybrid resonant reactance compensation scheme to obtain a hybrid resonant reactance compensation optimization scheme.

7. A series-parallel resonance reactance compensation system for power cable insulation testing, characterized in that: The hybrid resonance reactance compensation system for power cable insulation test includes a storage and a processor, wherein the storage includes a hybrid resonance reactance compensation method program for power cable insulation test, and when the hybrid resonance reactance compensation method program for power cable insulation test is executed by the processor, the following steps are implemented: Acquire historical insulation test data of the power cable, the historical insulation test data including historical test power parameters and historical power cable physical parameters, and construct a simulation model of power parameter changes of the power cable during the power cable insulation test according to the historical insulation test data; Obtain insulation test data of a target power cable to be tested for insulation, import the insulation test data into the power parameter change simulation model, identify the current fluctuation of the target power cable, and perform performance evaluation on a high-voltage reactor of the power cable insulation test according to the current fluctuation data to obtain a performance evaluation result of the high-voltage reactor; Constructing a performance parameter database of idle reactors, identifying the best idle reactor for reactance performance compensation of the high-voltage reactor according to the performance parameter database and the performance evaluation result of the high-voltage reactor, and constructing a hybrid resonance reactance compensation system with the high-voltage reactor and the best idle reactor; The resonance frequency of the target power cable during the insulation test is dynamically matched according to the hybrid resonant reactance compensation system to obtain a hybrid resonant reactance compensation scheme for the target power cable during the insulation test.

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